The present invention relates generally to a sheet film package and a device for loading sheet films, and more particularly to a sheet film package comprising a tray for storing a plurality of sheet films therein and a light-shielding cover peelably attached to the tray and closing a film access opening, and a cassette loading device in which the cover is peeled off the tray under light-shielding conditions for opening the film access opening, so that the sheet films can be loaded in a bright room.
X-ray films are widely used in the medical field for photographing objects such as human bodies with X rays for medical diagnosis. For photographing an object on such an X-ray film, it has been customary to load the X-ray film into an X-ray photographing device under a light-shielded environment and exposed the emulsion layer of the film directly to an X ray having passed through the object for recording the image of the object thereon.
There has recently been developed and widely used a radiation image recording and reproducing system for producing the radiation-transmitted image of an object using a stimulable phosphor material capable of emitting light upon exposure to stimulating rays. When a certain phosphor is exposed to a radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays, or ultraviolet rays, the phosphor stores a part of the energy of the radiation. When the phosphor exposed to the radiation is subsequently exposed to stimulating rays such as visible light, the phosphor emits light in proportion to the stored energy of the radiation. The phosphor exhibiting such a property is referred to as a "stimulable phosphor".
In the radiation image recording and reproducing system employing such a stimulable phosphor, the radiation image information of an object such as a human body is stored in a sheet having a layer of stimulable phosphor, and then the stimulable phosphor sheet is scanned with stimulating rays such as a laser beam to cause the stimulable phosphor sheet to emit light representative of the radiation image. The emitted light is then photoelectrically detected to produce an image information signal that is electrically processed for generating image information which is recorded on a recording medium such as a photosensitive material or displayed as a visible image on a CRT or the like.
The visible image thus produced may be recorded on a recording medium by an image recorder such as an image output laser printer, for example. In the image output laser printer, photographic films stored as a recording material in a magazine are loaded, and taken out one by one by a sheet delivery device such as a suction disk. Thereafter, the film is exposed to a laser beam modulated by an electric signal produced from the stimulable phosphor sheet for recording an image on the film. The exposed film is then transferred into an automatic developing device and processed thereby to develop the image. The film is thereafter stored in a prescribed place for use in medical disgnosis when required.
When loading the films into the image output laser printer, they must not be exposed to extraneous light. Therefore, it is general practice to load the films into the image output laser printer in a dark room, but the efficiency of such a loading process is low. There is a strong demand for the loading of films under bright conditions such as in an ordinary bright room, and various methods have been proposed for loading films in bright environments. One such method is disclosed in Japanese Laid-Open Utility Model Publication No. 56(1981)-07931.
FIG. 1a illustrates in cross section a conventional sheet film magazine 1 to be loaded into an X-ray photographing device. The film magazine 1 includes a casing 2 and a cover 3 openably hinged to the casing 2, the casing 2 and the cover 3 jointly defining a chamber 4. Gripper rollers 5a, 5b are rotatably supported respectively on the casing 2 and the cover 3. A light-shielding member 6 is disposed between the casing 5 and the cover 6 for preventing extraneous light from entering the chamber 4 through the gripper rollers 5a, 5b.
The cover 3 has a film access opening 7 that can be opened and closed by a shutter 8 mounted in the cover 3, the shutter 8 having a bent grip 9 on one end thereof. A sheet film package 10 is housed in the magazine 1. The sheet film package 10 accommodates a plurality of unexposed sheet films 12 protected by cardboard 11. The sheet film package 10 has opposite ends 10a, 10b exposed out of the magazine 1.
For loading the sheet film package 10 under a bright condition, the end 10a of the package 10 is engaged by the grip 9 of the shutter 8, and the other end 10b is cut off by scissors or the like. Then, the magazine 1 is loaded into an X-ray photographing device 13 (FIG. 1b), and the shutter 8 is manually pulled from the magazine 1.
As a result, the package 10 is engaged by the grip 9 and drawn out of the magazine 1. Since the package 10 is gripped by the gripper rollers 5a, 5b, the unexposed films 12 are left in the chamber 4. As the shutter 8 is pulled out, the film access opening 7 is opened to expose the chamber 4 of the magazine 1 into the X-ray photographing device 13.
The unexposed films 12 are successively attracted by a suction device or suction disk 14 and delivered to a prescribed photographing position.
Another known device is disclosed in Japanese Laid-Open Utility Model Publication No. 56(1981)-05141. FIG. 2a shows in cross section a disclosed sheet film package 15 to be supplied to an X-ray photographing device. The film package 15 includes a light-shielded or sunproof container 17 in the form of a box having an opening 16. The light-shielded container 17 contains a pluraltiy of unexposed films 19 protected by cardboard 18. A flexible light-shielding member 20 is applied over the opening 16 in light-shielding relation to protect the unexposed films 19 from exposure to extraneous light. One end of the flexible light-shielding member 20 is curved upwardly and has an engagement hole 20a defined near its edge.
The film package 15 of the above construction is positioned by a storage unit 22 housed in a magazine 21 as shown in FIG. 2b. The magazine 21 has a shutter 23 having an engagement pin 24 mounted on one end thereof. After the engagement pin 24 has engaged in the hole 20a of the flexible light-shielding member 20, the magazine 21 is loaded into an X-ray photographing device (not shown), and the other end of the shutter 23 is pulled out of the magazine 21 by fingers. As a result, the flexible light-shielding member 20 is peeled off the container 17 by the pin 24 engaging the hole 20a, and the opening 16 is opened in the X-ray photographing device. The uppermost unexposed film 19 is then attracted by a suction device 25 and delivered through the opening 16 into a given photographing position.
With the illustrated conventional device, however, the dedicated magazine 21 must be used to store the film package 15. This magazine must be of a rugged construction capable of withstanding stresses due to repeated attachment and removal thereof, and hence is considerably heavy. Therefore, it is laborsome for the operator to load and unload the magazine. The magazine is also considerably expensive since it has a shutter mechanism. Where various films of different sizes are to be employed, there must be used as many dedicated magazines as the number of those different film sizes, and the cost of manufacture is so high that they are economically infeasible in reality.
In order to load the films into the X-ray photographing device, it is necessary to attach the shutter to the end of the film package or the light-shielding member, and pulling out the shutter after the magazine has been placed into the device. As a consequence, the film loading process of the above nature is tedious and considerably time-consuming.